In recent years, the ad-hoc network in which a plurality of wireless communication terminals are connected to each other in an autonomous distributed manner has been studied. Hereinafter, a wireless communication apparatus is simply referred to as a node. In the ad-hoc network, no access point is installed and each node transmits packets having been received from an adjacent node to a destination by relaying the packets based on communication path information.
Each node transmits information on a received signal strength indication (RSSI) by transmitting and receiving a hello packet and retains a sum value of the RSSI from the own node to a destination for each path. The RSSI indicates a signal strength. For example, the RSSI is converted into an evaluation value of a wireless link quality and used. A sum value of the evaluation values of wireless link qualities from the own node to a destination is referred to as ΣPav. When a plurality of paths destined for the destination are present, the node selects a path with a higher transmission quality with reference to ΣPav corresponding to the paths and transmits packets.
FIG. 16 is a diagram illustrating an exemplary technology of the related art. As illustrated in FIG. 16, an ad-hoc network includes a gateway (GW) 5 and nodes 10a, 10b, and 10c. Two kinds of paths, path A and path B, are present as the paths destined from the node 10c to the GW 5. When the node 10c transmits packets to the destination GW, the node 10c compares ΣPav of path A to ΣPav of path B, selects the path with a better communication quality, and transmits the packets. For example, when path A has the better communication quality, the node 10c transmits the packets to the node 10a. Then, the node 10a transmits the packets to the GW 5. An example of the related art is Japanese Laid-open Patent Publication No. 2007-235719.
The above-mentioned technology of the related art has a problem that information, such as the number of hops, a link RSSI, a topology, and the like, used to construct the paths is not efficiently collected.
Information on the number of hops, the link RSSI, the topology, and the like is used in order to save the bandwidth when the paths are constructed in the ad-hoc network. In the technology of the related art, when each piece of information is collected, each node separately transmits operation data. Therefore, the traffics increase in the ad-hoc network. Further, to obtain information on the topology, the node adds local information to the operation data when the node transmits the operation data. Therefore, the amount of data regarding the operation data increases, and thus the amount of traffic further increases.